Carburetor



`une 7 1927.

w, T. SIMPSON CARBURETOR Filed Oct. 2l 1920 Patented .lune 7; 1927.

UNITE@ l 1,631,701. PATENT OFFICE.

wenn fr. simpson, or ANN Annen, MICHIGAN, AssIGNoR,.BY MESNE ASSIGNMENTS,

'ro ALBERT e. DICKINSON, or GRAND RAPIDS, MICHIGAN. f

CARBURETORQ Application filed October 21, 1920. Serial No. 418,418.

One object of my present invention is to providev means for controlling the flow of air to the fuel nozzle and mixing` chamber to meet the different conditions, in starting. idling., or ruiming with wide open throttle.

Another object of my invention is to pr0 vide means for catchinganyfuel which Vmay collect and drain back fromthe'walls of the intake or manifold during idling and for causing this lfuel to be carried yinto the manifold when the throttle is openedl vfor acceleration.

, Other objects of my invention will appear hereina'fter.v

In the accompanying drawing:

Figure 1 is a vertical sectionalfview Yof a carburetor embodying the invention.

2 is a detail view of a metering valve and a fuel tube.

Fig. 3 is a cross sectional view of the throttle valve, and air and fuel nozzle and meter valve. Y

Figs. 4i and 5 are detail sectional. views of modiiied forms of balanced fuel inlet valve.

Fig'. 6 is a side view of` an lautomobile showing the carburetor attached thereto.

ln these drawings the invention is shown in connection witha carburetor designed. to lift fuel to its nozzle from a low level'tanlr without the interposition of *an lelevated. if'acuum chamber or supplemental fuel chamber, a vacuum being maintained in the fuel chamber of the carburetor, which will draw thereinto through a balanced inlet valve the necessary fuel supply. i'

The fuel chamber is shownat 1r the mixing tube or chamber at '2. At3` is shown a passage connecting the fuel'chamber with the engine intake and this passage is in coinmunication with the mixing"` lchamber through a narrow annular passage 4 between the wall of the mixing tube and the wall of the carburetor casing. I

rihe mixing chamber .or tube extends through the casing' at 5 and lsurroundin'lgrr its lower end is the throttlevalve 6 which is in the form of asleeve whicln when in closed positioin seats itself with its lower edge resting' on'the iiang'e or plate i" which isarraixg'ed oppositethe lower intake opening of the mixin'g'tube, This throttler seat member Vis open 'at its center and rising from the edge Aof this opening is. a conical tubular member S. Through thistubular member the fuel tube 9 extendsy toa point above the same,`

this tube at its lower end extending into the fuel chamber through a suitable bearing at 10. The valve seat member is formed at the upper end of a easing or box-like structure 11 which is attached by. a screw thread at- 12 to the upper end of the bearing. This casing has an air inlet at 13 controlled by a' small valve 14 which is 'operable through any suitable connections 15.

Surrounding the upper end of the fuel pipe 9 a main air nozzle 1'6 which is tapered upwardly lboth onv its interior and exterior. The lower end of this air nozzle eX- tends to a point slightly below'the level of the upper end of the conical tube and there is a' restricted annular space at 16a between these parts. The air nozzle is supported upon posts 17 extending upward from the throttle valve seat. Thel part' 8 may be termed a supplemental air nozzle as air vpasses therethrough around the Vfuel tube and into the main air nozzle. d

The throttle valve :may be raised and ylowered on the outsideof the mixing chamber or tube in any suitable way, as by rotating it on pins engaging spiral grooves therein. The rotating means may be any suitable rod and arm or other connection. This rod will extend to the dash. Any suitable vlever or arm connection may be made tween the rod and the throttle valve.r

The outer side of the tubularcone 8 has serrations to present obstructions or deflectors to theV free flow of t-he'air into the interior of the airtube through the restricted annular' passage'16f. e

Fuel is made to lflowv upward in the fuely tube not aloneby the direct suction of the engine or the depression in the mixing space but by aid of the arrangement or construction of the various tubes comprising the nozzle, which are so formed that when air rushes by their upper ends due to the depression in 'the'chamber-Q, a partial vacuuinis formedv directly above the end of the fuel tube suff- {icient to draw up fuel as needed to operate the engine efficiently under all conditions of operation.- This action ofV the air in creating a vacuum at the vend ofthe mass along which it'passes'has been referred to' as its aspirating effector action.` i i v e l.Vraie the serrations above referred to not introduced, during the idling of the motor, the velocity of the air current upward along the sides of the tubular cone would causeA too great a quantity of fuel to be drawn from the fuel pipe. To operate properly, these serrations would ordinarily have to be constructed nicely as to size, and, as precision work of this sort increases expense, a means has been provided to eliminate precision. The approximate size of the serrations being known by experimentation, they are ina'de somewhat larger than is necessary, thus retarding the flow of air more than is desired. To bringthis liow up to the desired point a small air valve i4 is made which can be adjusted to provide the amount of air needed. lt is less expensive to provide this valve than to machine the serrations accurately to size.-

For startingr the throttle valve is closed and the air valve 14 is `wide open, so ,that all the air passes through the interior of the air nozzle and a rich mixture ismade by the air current pulling on the fuel.

' A metering valve is shown at i8 operated by a rod 19 and a spring 20. This rod passes through a packing gland at 23 and at its lower end it hears on the iiange 24; formed withv or attached to the metering pin. The rod 19 is screw threaded at 25 into the frame so that by turning` this rod the metering pin may beadjusted. f

VVheii-idlingj, at whichtime the throttle valve is nearly closed., there may not be sufficient air flow to carry up the fuel that precipitates on the manifold lof the engine.

Some of this precipitated fuel will collect and drain back into the cupshaped channel 2l.. A. small tube 22 rises out of the channel 2l and enters slightly into the passage 2. with its endr directed atan angle upward. toward the engine intake. throttle is opened. and the rush of mixture up through the passage 2 is at high speed, the aspirating action of this upward rush will create a. sufficient Vacuum just at the end of the tube 22 to draw up through said tube the. precipitated fuelwhich has drained vinto the channel 21.

{Tlie fuel inlet valve is balanced so that despite the vacuum in the fuel chamber, .it

will be under the infiueiice of the float alone and will not be affected. by the vacuum pres- The valve is shown at 26 slidably mounted on a recessed standard Q7 having'a. transverse space or passage 25%. This recessed standard extends up from the bottom of the fuel chamber. The upper end of the valve stein is exposed in a chamber 29 to which atn'iospheric air has access-through a suit- Vh en the The vacuum depression acts on equal areas exposed upwardly and downwardly.

The float 30 moves vertically on` the outer side of the recessed standard, it being provided with a central olviening receiving; the recessed standard. The valve stein has a grooved collar 31 'engaged by levers 32V for instance, byV using` a hollow valve stein 35, Fig. 4;. so that the fuel can reachk the chamber at the top of the valve'stem and Y act on the upper end of the stem with equal effect in respect to its action on the `lower end of the stem or a passage 36 may be used as in Fig. 5 to connect the fuel conduit with the chamber above the valve stein for the saine purpose.

The serrations orequivaleiit means for retarding the flow of the air are of use when the throttle valve is anterior of the nozzle and iniXini;-v chamber, substantially inthe posi-k tion shown, and past which anterior valve va high velocity flow of air is induced by the depression in the manifold. lith a throttle valve posterior to the nozzle the serrations would be of no utility.

It will be observed that-the primary air passes through the valve 14- and lower nozzle MJU 8 and into the nozzle 16 across theannular space and that this annular space communicates with the secondary airspace surrounding tlie nozzles and lying between them. and i the wall of the mixing tube, and that this secondary air space is controlled by the valve 6. The primary and secondary air supplies are controllable independently of each other.

I claim'as my invention 1. In combination in a.v fuel supply and carburetion system Van air tight fuelV chainber, afuel tubeleadinp; from the lower. part thereof up toward av mixing chamber which is in direct cominunicatioii with said fuel chamber. said direct communication keepiner the pressures in mixing. chamberand iin fuel chamber always substantially equal and holding the fuel inbalance, and an air nozzle surroundingy the fuel tube and liafvin'ga passage between itself and the fuel tube for receiving andV directing air at high velocity along and by the end of the fuel tube for drawing fuelA therefrom, a supplementalV nozzle extendingv into rthe lower part` of the main lair nozzle and spaced apart therefromV to provide an annular air inlet-for Vairyat high velocity at the lower fend of the. first mentioned air nozzle.y the upper end of the air nozzle being fiared outwardly to provide a restriction between itself and the wall of the mixing chamber to increase the flow of air by the fuel tube when the high velocit-y air is not available. v

2. In combination, a mixing chamber, a fuel chamber, a fuel pipe, a main air nozzle within the mixing chamber and surrounding the upper end of the i'uel pipe and spaced apart therefrom, a supplemental nozzle within the mixing chamber, surrounding the fuel pipe and having its upper end discharging its air into the lower end of the main nozzle, said nozzles having an annular passage between them for the induction of air from the space rbetween the supplemental nozzle and the wall of the inizing'chamber, an anterior valve to control an air supply to the mixing chamber, means vfor controlling the air through the Supplemental nozzle, and meansI on the exterior of the supplemental nozzle adjacent the base thereoitf Afor ob structing or retarding the how oic air let in by the throttle Valve, during idling.

' 3. lin combination, a mixing chamber, a

Yuel chamber, a fuel. pipe, a main air nozzle within the mixing.chamber and Surrounding the upper end ol' the fuel pipe and spaced apart therefrom, a supplemental nozzle within the mixing chamber, surrounding the fuel pipe and having its upper end di. vcharging its air into the lower end of the main nozzle, said nozzles having an annular passage between them for the induction of air from the space between the supplemental nozzle and the wall of the mixing chamber, an anterior valve to control an air supply to the mixing chamber, means `for controlling the air through the supplemental nozzie, and means on the exterior oit the supplemental nozzle adjacent the base thereotl for obstructing or retarding the flow oft' air let in by the throttle valve, during idling, said means consisting ot' serrations or deliectors on the exterior of the supplemental nozzle,

vsubstantially as described.

Ll. ln combinationin a carburetor, a -liuel chamber, a mixing chamber, a 'luol pipe extending into the same coaxially therewith, an air nozzle surrounding the upper part of the 'luel pipe with an air space between its interior and the liuel'pipe and between its exterior and the wall oli the mixing chamber, a supplemental nozzle substantially at the int-alie opening of .the mixing chamber, said supplemental nozzle discharging into the lower end of the main nozzle and having an air passage between its discharge end and the interior oi the main nozzle, a Valve in the form or a sleeve surroundingr the intake end oi' the mixing chamber, a seat therefor opposite said intake end and spaced apart therefrom for the intlowof air when the valve is opened, the opening of said valve admitting air to the space between the nozzles and the wall ot the mixing tube and to the annular space between the supplemental nozzle and the interior of the main air nozzle, and means for controlling the supply of air through the vsupplemental nozzle, substantially as described.

5. in combination in a carburetor, a fuel chamber, a mixing chamber, a fuel pipe eX- tending into the same coaxially therewith, an air nozzle surrounding the said pipe at its discharge end, an air directing member surrounding the fuel pipe and having its upper end extending into the lower end of the air nozzle with an air space between, a valve seat arranged opposite the Vintake opening oit the mixing chamber, and from which. said air directing member extends, and means on the outerside ot' the said di= recting member 'tor obstructing lSaid annular air space leading into the lower end of the air nozzle to retard the flow ot air to Said space duri ng idling, and a 'valve controlling the air supply to the said air intake.

G. ln con'ibination in a carburetor, a fuel cban'iber, a mixing chamber, a fuel pipe eX- tnding into the same coaxially therewith.l anair nozzle surrounding the said pipe rat its discharge end, an air directing member surrounding the fuel pipe and having its upper end extending into the lower end ol the air nozzle with 'an air space between, a valve seat arranged opposite the intake opening et the mixing chamber, and 'from which said air directing member extends, and means on the outer side of the said directing member for obstructing said annular air space leading into the lower end of the air nozzle to retard the flow oi' air to said space during idlir and an anterior Valve controllingthe an apply to the said air intake` said air retarding and detlecting means being disposed au various points along the said air directing member in the direction of the opening and closing movement of said throttle valve.

ture.

WARD T. SIMPSON.

ln testimony whereof, I allix my signa- 

